Conventional concrete members will be manufactured with a constant grain size distribution over the cross section of structural members (slabs, walls, girders etc.). The attempt of positioning of the aggregate (1) in different layers already fails during the compaction by vibration. The result is a random distribution of the aggregate (1) over the cross section and a large scattering of the material performance. A stress-strain curve of a loaded beam has in contradiction of theoretical assumptions no consistency of the cross sections. The strain curve of the compression zone and the tension zone are different (see FIG. 6). The strain in the tension zone of the member is larger than in the compression zone. Conventional concrete members have no positioning and variation of the aggregate size and therefore only a more or less constant stiffness (large stiffness) over the cross section. Consequently the members tend to crack by a small strain. The cracks of reinforced concrete members can only be minimized to w=0.20 mm. The minimum crack width of 0.20 mm doesn't satisfy the requirements of impervious overlays [Lit.1]. In addition reinforced concrete members have a required concrete cover of the reinforcement of at least 25 mm. Consequently the load cannot be taken by the overall cross section of the member and the dead load of the member increases.